With sustainability and efficient building becoming a priority in today’s increasingly climate-conscious world, there is one form of construction that seems to be on the up-and-up.
“Prefab”, or modular construction, is a high quality, affordable solution for public and residential buildings that offers far better sustainability outcomes.
Images: GoLogic / Plant Prefab
What is “prefab”?
When it comes to building construction, there are essentially two different options.
The traditional form of construction widely practised is “stick built”, which means buildings are constructed from the ground up on-site, as you would see in a typical home build.
Prefabricated, or modular construction, is when all or part of a building is built inside an off-site warehouse and then assembled on-site.
Images: Canva / ARKit Advanced Prefab
The term “prefab” simply refers to structures that are built or prepared or assembled off-site away from the building site. In the modern world, it is difficult to find a building that doesn’t contain prefabricated elements. Think of a window for example. The window is (typically) built in a warehouse and then transported to the site to be inserted whole into the building. So when it comes to a building, we’re talking about degrees of prefabrication.
The process is relatively broad, and typically involves two main types of construction:
- 2D panel systems: used to create walls, internal stairs and the building envelope. It makes customised design easier and quicker to assemble than other construction techniques.
- 3D modular systems: volumetric systems usually comprised the wall, ceiling and floor of a single room. This is much faster as components arrive at the construction site almost complete.
Why is prefab becoming more popular in Australia?
- affordability: prefab is considerably cheaper because the production process is more streamlined, there is less labour needed, and there is less waste. For this reason, it is already being used for quarantine facilities, educational buildings, remote accommodation, temporary housing and social housing for vulnerable communities.
- speed: the speed and precision of the technique is what makes it so affordable. It is much faster to put together a house that has been pre-fabricated on the warehouse floor. Houses can be finished within a matter of days or weeks, not months.
- quality: as the building parts are constructed and cut to size by machine rather than by hand, the risk of mistakes and miscalculations is eliminated. When assembled, the building envelope is tighter.
- climate resilience: PrefabAUS is working with the Bushfire Council of Australia to create a model for a bushfire resilient house. It is also working on flood resilient floating houses as well.
- less waste: all materials are cut to size, and some are even 3D printed. Recycling can be streamlined. There is less of a waste problem than in traditional stick-built construction, and less energy is needed.
- less disturbance: because the manufacturing process can be so streamlined and controlled, and because the building construction on-site is so fast and efficient, the possibility of disturbance of the environment is far reduced. Pollution, including sound pollution, on-site is nearly eliminated.
- reusable at end-of-life: if the building is no longer needed, it can be dis-assembled and the materials can easily be reused.
- gender equity: we all know the construction industry has a big problem with gender equity (women make up just 2.5 per cent of tradies and on-site construction workers, according to Monash University). Prefab is being touted by those in the industry as a possible solution to delivering greater gender equality on the construction site, breaking down the proverbial “concrete ceiling”.
Problems with prefab
While there are so many benefits to prefabricated construction, there are a few things that can make it less desirable, especially to home builders.
- no change of mind: the main drawback is that once the panels and structures have been created, there is little to no opportunity to alter the shape or make dramatic aesthetic changes to the design, whereas traditional “stick built” construction allows for modifications at the construction stage.
- Issues with transportation: transporting building parts can be a little more complicated, especially in rural areas. And issues with transportation and assembly factors can lead to damage to the prefabricated unit, which will need to be repaired. While this might be a bit more difficult to organise, the reduced cost of labour on the construction site means that it can still be a more attractive option for rural or remote builds, where labour will need to be brought in and out.